Killers sent to plague us

The human cost of history's lethal epidemics defies imagination, and they might not have finished with us yet

FOR MOST OF us living in the cosmetically-enhanced, youth-venerating, mortality-denying West, the belief that science has conquered disease is an almost irresistible self-delusion. Of course, there has been the occasional scare - witness Aids and BSE - but solutions to these are widely assumed to be a matter of time.

This new book, a chilling warning from history, offers a timely challenge to our complacency. Surveying the last two millennia's-worth of ultra-destructive lurgies, it points out that the trend in the West has not been an ever more healthy onwards march from disease-ridden antiquity to super-hygienic modernity. Instead, long centuries of epidemic have alternated with equally long periods that were almost totally plague-free, like our own.

The Roman world, Doctors Naphy and Spicer argue, was curiously free of major epidemic disease. Of course, the Grim Reaper visited in other guises, notably smallpox and measles (which seem to have hit the Roman Empire in around ad 170 and 250 respectively). But these were predominantly diseases of children. Those who survived were immune.

Then, apparently from nowhere, came the First Great Pandemic. This as yet unidentified virus hit Europe, the Levant and North Africa in ad 541, with recurrent outbreaks roughly every decade for the next 200 years. Between ad 541 and 600, the population of the Roman Empire was reduced to something between 30 and 50 per cent of its pre-plague levels. Large parts of the Middle East, Egypt and North Africa - once the breadbasket of the Roman world - did not recover their pre-ad 540 populations until the end of the 19th century.

However, the next five centuries - roughly from Charlemagne's coronation in ad 800 through to the 1340s - were relatively horror-free. The early medieval world still had its killer diseases, but nothing on the scale of the earlier plague.

This period of rosy-cheeked remission came to violent end in 1347, with the arrival of the Second Great Pandemic: the "Black Death" - or bubonic plague - that was to become a recurrent feature of European life for the next 400 years. But it was not a purely European phenomenon. This sensationally ferocious bug originated in Mongolia in the 1320s and spread rapidly throughout Asia and along the Silk Road to the West. China succumbed first, in 1331, losing an estimated 65 per cent of its population in the next 20 years. The plague reached the Mediterranean in 1347 and the British Isles the following year.

Even to us, accustomed to the 20th-century's hecatombs of slaughter, the scale of the Black Death's casualties is almost beyond imagining. Most estimates agree that something like 30-40 per cent of the population perished in the first epidemic of 1348. Of those that survived, another 20 per cent were killed in second outbreak of 1361; and a further 15 per cent perished in a third outbreak, in 1369. To put these figures into context: if the Black Death were to hit the European Union today with the same intensity as in 1348, the result would be 108 million dead.

Nor was 1369 the last of it. Thereafter, the Black Death returned to most European cities, albeit with less violence, every six to 12 years, until it disappeared - for reasons that have never been adequately explained - around the beginning of the 18th century. England's last major epidemic was the outbreak of 1665 - famously chronicled by Samuel Pepys; though there was an outbreak of bubonic plague in Glasgow as late as the 1890s.

There is more to this book, however, than a relentless catalogue of corpses. For Naphy and Spicer, the grim statistics are merely the starting point for inquiries into the social responses these recurrent calamities provoke. The most common reaction to these visitations was to regard them as acts of divine censure: punishments meted out by a wrathful God to avenge himself on the sinful (though, interestingly, the Muslim world regarded dying of plague as a blessing, ensuring immediate entry into Paradise).

Another was the quest for scapegoats. If the deity was displeased, then it followed that there must be a reason for his displeasure. Since this self-evidently could not be against virtuous Christians, outbreaks of the plague regularly triggered pogroms against Jews, beggars, and (particularly in Florence and Venice) homosexuals. Although Clement VI (1342-52) and subsequent Popes repeatedly condemned attempts to blame Jews for the outbreaks of the pestilence, their attempts to halt the Jewish persecutions were largely unavailing.

This book suggests a further hypothesis: that while the motives for religious belief cannot of course be reduced simply to the fear of death and dying, the randomness of mortality in the three centuries after 1348 may have given a particular intensity to religious experience (and religious divisions) during this "great age of plague".

It remains striking that the waxing and waning of ecclesiastical conflict in Europe - from the Great Schism of 1378 through to the end of the Thirty Years' War in 1648 - corresponds with some exactitude to the terminal dates of the "Age of Plague". Conversely, the 18th-century Enlightenment took place in a world in which plague had all but disappeared. In the age of Rousseau and Fragonard, if God was still in his heaven (and some doubts were beginning to creep in), at least he seemed in far better humour.

It would be nice were this the end of the story. In fact, there was a Third Great Pandemic in the richly irreligious 1890s. This ravaged Canton, Hong Kong, Sydney, Bombay, and Glasgow, and provided the French microbiologist Alexandre Yersin with the opportunity to isolate (and give his name to) the bacillus that had caused all the bubonic troubles of the past. However, as Dr Naphy and Dr Spicer point out, there is strong evidence to suggest that the bacillus of 1894 had mutated considerably from its bubonic ancestor of 1348-1720 - and may yet do so again. It is far from clear that we have heard the last of Yersinia pestis.